Superconducting circuits may include wires made of superconducting materials or, simply, superconductors. Other components of the superconducting circuits may include dielectrics. Often, the dielectrics act as sources of microwave absorption, which are believed to be caused by defects and/or two-level systems (TLSs). Optimizing dielectric materials and processing conditions during fabrication of the dielectrics may reduce the number of defects and TLSs. However, precise controlling the dielectric materials and processing conditions can be expensive and some defects and TLSs generally remain and still cause microwave absorption even with precise control.